1. Field of the Invention
The present invention relates to a bag-making and packaging machine that includes both a bag-making apparatus and a bag-filling packaging apparatus.
2. Prior Art
Bag-making and packaging machine are described in, for example, the specifications of Japanese Patent Application Laid-Open (Kokai) Nos. 56-113522 and 2002-36392 and U.S. Pat. No. 5,862,653, and such a bag-making and packaging apparatus includes a bag-making apparatus, a bag-filling packaging apparatus and a bag transfer apparatus.
The bag-making apparatus manufactures bags by performing a bag-making operation such as folding and overlapping by a forming apparatus, a sealing operation of the bag bottom portions and corresponding locations on the side portions of the bags by a sealing apparatus, and a separation operation of the bags by cutting by a cutting apparatus, etc., while unwrapping a film from a film roll whose axial center is disposed in a horizontal attitude and feeding this film in the direction of length. The bag-filling packaging apparatus grips both side edges of the bags by grippers, thus suspending the bags, intermittently moving these suspended bags along an annular path, and performing packaging operations such as filling of the bags with contents and sealing of the mouths of the bags, etc. at respective stopping positions. The bag transfer apparatus receives bags at a receiving position at the final end of the bag-making apparatus, conveys these bags to a transfer position, and transfers these bags to the grippers of the bag-filling packaging apparatus.
In the conventional bag-making and packaging machine, the bag-making apparatus folds the film in two and overlaps the film in the vertical direction (so that the bag mouth side is on top) in the central portion while unwrapping the film from a film roll whose axial center is disposed in a horizontal attitude and feeding this film in the direction of length, and then the bag-making apparatus performs bag-making operations such as sealing and cutting (cutting into respective bags), etc. on this film.
The bags that are cut from the continuous film are received by the bag transfer apparatus and are transferred to the grippers of the bag-filling packaging apparatus.
In the conventional bag-making and packaging machine, it is sufficient if bags that are manufactured in a vertical attitude are transferred in this attitude to the gripper of the bag-filling packaging apparatus. Accordingly, the advantage is that it has a simplified mechanism.
On the other hand, it has some problems. (1) Since the film is fed with the side that forms the inside surfaces of the bag facing upward until the film is folded and overlapped, and since the bag mouth side faces upward following folding and overlapping, foreign matter such as dirt, etc. tends to enter the interiors of the bags. (2) The bags that are manufactured by the bag-making apparatus include self-standing bags in which the bottom side of the bag is thick. As a result, the cutting of the bags is always performed from the lower side (bag bottom side); however, in cases where defective sealing or defective cutting of the film occurs, defective bags that are discharged downward or that hang downward tend to become entangled with the cutting blades and swinging shafts of the cutting blades, thus leading to further defective cutting and stopping of the bag-making and packaging machine.
In order to improve productivity, in the bag-making and packaging machines disclosed in the above-described Japanese Patent Application Laid-Open (Kokai) No. 2002-36392 and U.S. Pat. No. 5,862,653, two bags are manufactured at one time, these bags are simultaneously transferred to two sets of grippers in the bag-filling packaging apparatus, and the filling operation performed in the bag-filling packaging apparatus is also performed simultaneously for two bags (such machines are called W type machines after the configuration in which two bags are lined up on the left and right). However, no W type bag-making and packaging machine has been disclosed that can easily handle changes (alterations) in the bag size (bag length and/or bag width).